Number of 0..2 arrays of length n with each element differing from at least one neighbor by 1 or less.

A221591

Number of 0..2 arrays of length n with each element differing from at least one neighbor by 1 or less.

Terms

    a(0) =0a(1) =7a(2) =17a(3) =49a(4) =139a(5) =393a(6) =1113a(7) =3151a(8) =8921a(9) =25257a(10) =71507a(11) =202449a(12) =573169a(13) =1622743a(14) =4594273a(15) =13007201a(16) =36825691a(17) =104260057a(18) =295178697a(19) =835703199a(20) =2366023849a(21) =6698632793a(22) =18965016483a(23) =53693322401a(24) =152015310561a(25) =430382282407

External references